STM32F103ZET6 之 ADC+TIM+DMA+USART 综合实验

2017-09-18 来源：eefocus

1、实验目的

1）使用 TIM1 触发 ADC，ADC 采集的数据通过DMA 传至内存，然后通过串口打印出采集的数据；

2）学会 DMA 传输数据并将数据进行保存；

3）验证ADC 的采样率与实际设置的是否相符。

2、硬件资源

1）指示灯

2）ADC

3）DMA

4）TIM

5）杜邦线

3、软件设计

void Adc_Configuration(void)
{
DMA_InitTypeDef DMA_InitStructure;
ADC_InitTypeDef ADC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOC, &GPIO_InitStructure);

/* Enable DMA1 clock */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
DMA_DeInit(DMA1_Channel1); /* 复位DMA1寄存器到缺省状态 */
DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address; /* 选择ADC1的数据寄存器作为源 */
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADC_Sample.Ch1Buf; /* 目标地址 */
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC; /* 设置DMA传输方向，外设(ADC)作为源 */
DMA_InitStructure.DMA_BufferSize = SAMPLE_COUNT; /* 设置缓冲区大小 */
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; /* 外设地址不自增 */
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; /* 存储器地址需要自增 */
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord; /* 选择外设传输单位：16bit */
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord; /* 选择内存传输单位：16bit */
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; /* 无需循环模式 */
DMA_InitStructure.DMA_Priority = DMA_Priority_High; /* 选择DMA优先级 */
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; /* DMA传输类型，不是内存到内存 */
DMA_Init(DMA1_Channel1, &DMA_InitStructure);
/* Enable DMA1 channel1 */
DMA_Cmd(DMA1_Channel1, ENABLE);
/* 配置ADC1 */
/* ADCCLK = PCLK2/2 */
RCC_ADCCLKConfig(RCC_PCLK2_Div2); /* ADCCLK = PCLK2/2 = 36MHz */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE; /* 连续转换静止 */
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC3; /* 选择TIM1的CC3做触发 */
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right; /* 数据右对齐,高位为0 */
ADC_InitStructure.ADC_NbrOfChannel = 1; /* 1个通道 */
ADC_Init(ADC1, &ADC_InitStructure);
/* ADC1 regular channels configuration */
ADC_RegularChannelConfig(ADC1, ADC_Channel_10, 1, ADC_SampleTime_1Cycles5);
/* Enable ADC1 external trigger conversion */
ADC_ExternalTrigConvCmd(ADC1, ENABLE);
/* 使能 ADC1 */
ADC_Cmd(ADC1, ENABLE);
/* Enable ADC1 DMA */
ADC_DMACmd(ADC1, ENABLE);
/* 使能 ADC1 复位校准寄存器 */
ADC_ResetCalibration(ADC1);
/* 检测复位校准寄存器 */
while(ADC_GetResetCalibrationStatus(ADC1));
/* 开始 ADC1 校准 */
ADC_StartCalibration(ADC1);
/* 等待校准结束 */
while(ADC_GetCalibrationStatus(ADC1));
/* 配置采样触发定时器，使用TIM1 CC1 */
ADC_SampleRate(ADC_Sample.SampleFreq); /* 修改采样频率 */
}
/*
* Function Name : ADC_SampleRate
* Description : 修改ADC的采样频率
* Input : - freq: 采样频率单位Hz
* Output : None
* Return : None
* Attention : None
*/
void ADC_SampleRate(uint32_t freq)
{
/* 配置定时器1第3通道CC3作为ADC1的触发源 */
uint16_t Period;
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_Cmd(TIM1, DISABLE);
/* 采样频率计算公式 : period = 72000000 / freq ; 1200 == 60KHz 采样频率 */
Period = 72000000 / freq;
/* Enable TIM1 clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_TimeBaseStructure.TIM_Period = Period;
TIM_TimeBaseStructure.TIM_Prescaler = 0; /* 计数频率 = 72000 000 / 18 = 4000 000 */
TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
/* TIM1 channel1 configuration in PWM mode */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = TIM_TimeBaseStructure.TIM_Period / 2;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OC3Init(TIM1, &TIM_OCInitStructure);
/* TIM1 counter enable */
TIM_Cmd(TIM1, ENABLE);
/* TIM1 main Output Enable */
TIM_CtrlPWMOutputs(TIM1, ENABLE);
}